Old incandescent lamps are, undoubtedly, getting obsolete. Not long ago, CFLs started replacing incandescent lamps rapidly. But, soon after, LEDs are becoming famous nowadays. All these types of lamps, even incandescent lamps, are used today to brighten our homes, offices, streets and many more. This article compares between these three types of lamps and helps you choosing the best.
An incandescent lamp has a very thin tungsten coil inside. As the coil is very thin, when current passes through it, it offers a high resistance. And due to this high resistance, electrical energy is converted into heat. This heat is enough to make the filament white-hot. And, thus, the filament glows because of the heat. The main drawback of incandescent lamps is that most of the electrical energy is wasted in heat. Generally, these lamps come in ratings of 60 W, 100 W and above.
In a CFL, there are two electrodes at the ends of the fluorescent tube. The fluorescent tube is filled with gasses – argon and mercury vapors. The electrodes cause a stream of electrons flowing in the tube. These electrons interact with mercury vapor atoms and make mercury vapor atoms excited. When those mercury vapor atoms fall back to the unexcited state, they release energy in the form of ultraviolet radiations. These ultraviolet photons collide on the fluorescent tube (which is coated with phosphor from inside). When those photons collide on the phosphor coating, it emits visible light radiations.
Generally, CFLs come in ratings from 8 W, 10 W, 15 W etc. Unlike in incandescent lamps, electrical energy is not wasted in producing heat. Hence, CFLs are much more efficient than Incandescent Lamps.
Light emitting diode is a PN junction semiconductor device which when supplied with a DC current emits visible light. LEDs have been around for many years. You have seen a small LED indicator many times, right? Your mobile phone probably has an LED flash, isn’t it bright enough being so small? LED lamps or bulbs are made by connecting many such LEDs in an array forming an LED panel. A driver circuit is used to rectify and regulate the supplied AC power and to feed the LED array. An LED light bulb is far more efficient than an incandescent lamp and a CFL.
Which one is good for your pocket?
A common 60-watt incandescent lamp costs even less than a dollar, which is much more cheaper than the other two. But, though, the initial cost is low, an incandescent lamp will turn out to be costlier with time. The table below compares the costs of incandescent vs. CFL vs. LED lamp.
|Wattage needed for 650-800 lumens*||60||8 – 12||6 – 9|
|Average lifespan (hours)||1,200||8,000||50,000|
|No. of bulbs needed for 50,000 hours of use||42||6||1|
|Total spent on purchasing bulbs (over 50,000 hrs)||$42||$12||$5|
|Total cost of energy (over 50,000 hrs)(at 0.15$/kWh)||$450||$90||$67.5|
*Lumens is a unit to measure the amount of visible light.
From the above table, it is clear that an LED bulb will save a lot of your money over time. Think of how much could you save just by replacing your old light bulbs. The rapid developments in LED technology are bringing more energy efficient, longer lasting and more affordable LED bulbs. So, you won’t be bothering to replace your old bulbs with efficient LED bulbs.
You can easily buy a CFL or LED Light bulb at amazon.